1. Field of the Invention
This invention relates to a bidirectional repeater in a data transmission system, and more particularly to a bidirectional repeater in a data transmission system of the type having a plurality of communication units connected to a common bus, which utilizes the fact that each of the communication units requests the exclusive use of the common bus for data transmission and sends out a response signal when permitted, and is adapted such that information transfer means is actuated by the response signal to transfer the information transmitted after the response signal.
2. Description of the Prior Art
In the data transmission system in which a plurality of communication units are connected to a common bus, the number of communication units connectable to the bus is limited for maintaining good impedance matching state of the line. In order to connect more communication units, it is necessary to insert a bidirectional repeater in the line.
In conventional bidirectional repeaters of this kind, its information transmitting direction is determined dependent upon which of its terminals receives a signal earlier than the other. However, since the information transmitting direction is determined after detection of the arrival of the signal at the repeater, a delay of the signal increases and, in the case of impulsive noise getting mixed in the signal, the determination of the information transmitting direction cannot be controlled correctly.